A method for recycling and utilizing laterite nickel ore metallurgical SLAG resources

Abstract

The present invention discloses a method for recycling and utilizing laterite nickel ore metallurgical slag resources, and belongs to the field of hydrometallurgical technology. The method comprises the following steps: alkaline leaching treatment of laterite nickel ore hydrometallurgical slag to obtain alkaline leaching solution and alkaline leaching residue; acid leaching treatment of alkaline leaching residue to obtain acid leaching solution and acid leaching residue; mixing the acid leaching residue, biomass reducing agent and additives and then subjecting the obtained product to a ball milling treatment, and subjecting the obtained product to a reduction roasting treatment to obtain a roasting product; mixing the roasting product with a dispersant and subjecting the obtained product to a secondary ball milling treatment, and subjecting the obtained product to a magnetic separation to obtain an iron concentrate. In the present invention, the biomass is carbonized and activated to obtain a biomass reducing agent with enhanced reducibility. The biomass reducing agent has low cost and is green and environmentally friendly. After the biomass reducing agent is mixed with the acid leaching residue in a specific ratio, it is reduced and roasted in a specific atmosphere and then magnetically separated to obtain an iron concentrate with high purity and yield

Description

[0001] Description

[0002] A METHOD FOR RECYCLING AND UTILIZING LATERITE NICKEL ORE METALLURGICAL SLAG RESOURCES

[0003] Field Of Invention

[0004] The present invention belongs to the technical field of hydrometallurgy, and speci fically relates to a method for recycling and utili zing laterite nickel ore metallurgical slag resources .

[0005] Background

[0006] Nickel is the main material for the preparation of new energy batteries . With the rapid development of the new energy industry, the demand for nickel resources is also increasing . At present , the process of hydrometallurgical extraction of nickel from laterite nickel ore has become a research hotspot . In the process of hydrometallurgical extraction of nickel from laterite nickel ore , a large amount of laterite nickel ore metallurgical slag will be produced .

[0007] At present , the treatment of laterite nickel ore metallurgical slag is mainly carried out through underground pressure filtration backfilling, deep sea landfill and direct deep sea discharge . However, due to the high iron content in laterite nickel ore metallurgical slag, direct landfill or discharge treatment will not only cause a large waste of iron resources , but also cause environmental pollution due to the presence of other harmful elements in laterite nickel ore metallurgical slag .

[0008] Therefore , it is urgent to propose a new processing method to solve the above problems existing in the prior art .

[0009] Summary

[0010] The obj ective of the present invention is to provide a method for recycling and utili zing laterite nickel ore metallurgical slag resources . In the present invention, by sequentially subj ecting laterite nickel ore hydrometallurgical slag to alkali leaching, acid leaching, reduction roasting and magnetic separation, not only an iron concentrate product but also a by-product sodium sul fate product and a calcium chloride product can be obtained, and the obtained non-magnetic material can be used to produce building materials or cement products . This method greatly improves the resource utili zation rate of laterite nickel ore metallurgical slag and has good economic benefits .

[0011] The present invention provides a method for recycling and utili zing laterite nickel ore metallurgical slag resources , comprising the following steps : subj ecting laterite nickel ore hydrometallurgical slag to alkali leaching treatment to obtain alkali leaching solution and alkali leaching residue ; subj ecting the alkali leaching residue to acid leaching treatment to obtain acid leaching solution and acid leaching residue ; mixing the acid leaching residue , a biomass reducing agent and an additive , subj ecting the mixture to a primary ball milling treatment , subj ecting the obtained product to a reduction roasting treatment , and obtaining a roasting product ; mixing the roasting product with a dispersant , subj ecting the mixture to a secondary ball milling treatment , subj ecting the obtained product to a magnetic separation, and obtaining an iron concentrate ; wherein, in the preparation process of the roasting product , the biomass reducing agent is obtained by subj ecting the biomass to carboni zation and activation treatment .

[0012] In the present invention, the inventors have found that after alkaline leaching and acid leaching of laterite nickel ore hydrometallurgical slag, impurities in the laterite nickel ore hydrometallurgical slag can be removed . Further, the biomass is carboni zed ( i . e . , the process in which the organic components of the biomass are converted into inorganic carbon after high-temperature treatment ) and activated ( i . e . , the carboni zed product is treated so that its pore structure is regulated and improved) to obtain a biomass reducing agent with enhanced reducibility, which is beneficial to further improve the iron recovery rate . The present invention uses carbon dioxide as an activating agent , and the process flow is relatively simple . The waste gas generated is mainly CO2 and water vapor, which has little pollution to the environment . In addition, the final biochar product has a high specific surface area, a developed pore structure, and a wide range of applications. The cost of the biomass reducing agent is low, and the utilization rate of biomass is improved. After the biomass reducing agent is further mixed with the acid leaching slag in a specific proportion, it is reduced and roasted with additives under a specific atmosphere, and then magnetically separated to obtain an iron concentrate with high purity. The recovery rate is equivalent to or even better than that of coal or other reducing agents (such as coke) prepared from coal as raw materials. In addition, the entire method has the advantages of short process, low cost, and good recovery rate.

[0013] In some embodiments, during the preparation of the alkaline leaching solution and the alkaline leaching slag, the laterite nickel ore hydrometallurgical slag includes the following components by mass percentage: 40-45% iron, 5-9% sulfur, 1.5-3% calcium and 3-6% aluminum.

[0014] In the laterite nickel ore hydrometallurgical slag provided in the present invention, Fe mainly exists in the form of Fe2Os, S and Ca mainly exist in the form of CaSCh, and Al mainly exists in the form of (H2O) AI3 (SO4 ) 2 (OH) e and NaAls (SO4) 2 (OH) e; and the moisture content of the laterite nickel ore hydrometallurgical slag is 27-28%.

[0015] It should be noted that the laterite nickel ore hydrometallurgical slag also contains other elements.

[0016] In some embodiments, in the preparation process of the alkaline leaching solution and the alkaline leaching slag, the alkaline leaching treatment step specifically includes: placing the laterite nickel ore hydrometallurgical slag in an alkaline solution, controlling the solid-liquid ratio to 1g: (4-10)mL, and stirring for 60-140min at a temperature of 60-90°C and a rotation speed of 200-400rpm; wherein the concentration of the alkaline solution is l-2mol / L, and the alkaline solution includes a NaOH solution and / or a Na2CO3 solution.

[0017] In the present invention, the laterite nickel ore hydrometallurgical slag is subjected to alkali leaching treatment, so as to remove the sulfur impurity element in the laterite nickel ore hydrometallurgical slag. In some embodiments, the preparation process of the alkaline leaching solution and the alkaline leaching residue further includes a step of evaporating and crystallizing the alkaline leaching solution to obtain a sodium sulfate product; wherein the evaporation and crystallization specifically includes: evaporation and crystallization for 160-200 minutes at a temperature of 75-95°C.

[0018] In the present invention, the alkaline leaching solution is evaporated and crystallized, so that the sulfur impurity element can be converted into a by-product sodium sulfate product, thereby further improving the resource utilization rate of the laterite nickel ore.

[0019] In some embodiments, in the process of preparing the acid leaching solution and the acid leaching residue, the acid leaching treatment step specifically includes: placing the alkali leaching residue in an acid solution, controlling the solid-liquid ratio to 1g: (4-10)mL, and stirring for 60-140min at a temperature of 60-90°C and a rotation speed of 200-400rpm; wherein the concentration of the acid solution is l-2mol / L, and the acid solution includes an HC1 solution.

[0020] In the present invention, the alkaline leaching residue is subjected to acid leaching treatment to remove the calcium impurity in the alkaline leaching residue.

[0021] In some embodiments, in the process of preparing the acid leaching solution and the acid leaching residue, the step of evaporating and crystallizing the acid leaching solution to obtain a calcium chloride product is also included; wherein the evaporation and crystallization specifically includes: evaporation and crystallization for 160-200 minutes at a temperature of 30-90°C.

[0022] In the present invention, the acid leaching solution is evaporated and crystallized, so that the calcium impurity can be converted into a by-product calcium chloride, thereby further improving the resource utilization rate of the laterite nickel ore.

[0023] In some embodiments, during the preparation of the roasted product, the steps of carbonizing and activating the biomass specifically include: crushing the biomass, heating it to 350-600°C at a rate of l-5°C / min for carbonization for 80-160 minutes under an inert atmosphere; further heating the resulting product to 350-600°C at a rate of l-5°C / min for activation for 40-70 minutes under a carbon dioxide atmosphere; wherein the biomass includes at least one of coconut shells , wheat straws , corn straws , bamboo , rice straws , peanut shells and branches , and the inert gas includes nitrogen and / or argon .

[0024] In the present invention, by sequentially carboni zing and activating the biomass , a biomass reducing agent with enhanced reducibility can be obtained, and the biomass raw material is easily available and environmentally friendly .

[0025] In some preferred embodiments , the activated biomass is also subj ected to the steps of grinding, sieving, removing impurities and drying to obtain the biomass reducing agent .

[0026] In some more preferred embodiments , the grinding includes grinding with an agate mortar and / or a ball mill , the aperture of the sieve is 40-300 mesh, the impurity removal includes rinsing with deioni zed water 3-5 times , and the drying includes drying at a temperature of 110- 120 ° C for 680- 800 minutes .

[0027] In the present invention, the particle si ze of the biomass reducing agent is controlled within a specific range , the speci fic surface area is increased, and the activity of the biomass reducing agent is improved .

[0028] In some embodiments , in the preparation process of the roasted product , the amount of the biomass reducing agent added is 2-5% of the mass of the acid leaching residue , the additive is Na2CO3 and / or NaOH, and the amount of the additive added is 4- 6% of the mass of the acid leaching residue ; the first ball milling treatment step speci fically includes : ball milling in a ball mill for 30- 120 minutes ; the reduction roasting treatment step speci fically includes : placing the mixed substance in an atmosphere furnace , while introducing an inert gas at a flow rate of l-5mL / min; and heating to 500- 900°C at a rate of 3- 6°C / min for roasting for 30- 180min; wherein the inert gas is preferably argon . The present invention can reduce the melting point and save energy consumption by adding Na2CO3 and / or NaOH as additives during the roasting process , and at the same time , it is beneficial for some substances in the leaching residue to react to form sul fides , which is convenient for removal through the subsequent magnetic separation process , and finally further improves the purity of the iron concentrate ; at the same time , the inventor found in the experimental process that compared with nitrogen, using argon as an inert gas is more conducive to improving the purity of the iron concentrate . In the present invention, after a ball milling treatment , on the one hand, the mixed materials are further mixed evenly, and at the same time , the particle si ze of the mixed materials is made smaller, which is conducive to the reduction roasting reaction; further, by controlling the amount of the biomass reducing agent within a speci fic range and controlling the flow rate of the mixed gas , the acid leaching residue can be ef fectively reduced to obtain an iron concentrate with higher purity and yield .

[0029] In some embodiments , during the preparation of iron concentrate , the amount of dispersant added is 3-5% of the mass of the roasted product , and the dispersant includes at least one of sodium metaphosphate , sodium hexametaphosphate , water glass , caustic starch and salted water glass ( i . e . , a mixture of water glass and aluminum sul fate ) ; the secondary ball milling treatment step speci fically includes : the ball milling time is 20-40 minutes .

[0030] In the present invention, the use of a dispersant facilitates ball milling to obtain a mixture with a smaller particle si ze , and also facilitates subsequent magnetic separation .

[0031] In some embodiments , in the preparation process of iron concentrate , before the obtained product is subj ected to magnetic separation, the steps of adding water to the obtained product for slurry treatment to obtain an intermediate slurry and subj ecting the intermediate slurry to magnetic separation are also included; wherein the mass of the added water is 4- 6 times the mass of the obtained product ; the magnetic separation speci fically includes : conducting magnetic separation under the condition of a magnetic separation intensity of 1000-3000GS .

[0032] In the present invention, magnetic separation is performed at a speci fic magnetic separation intensity to obtain an iron concentrate with higher purity .

[0033] In some preferred embodiments , the step of producing building materials and / or cement products from the non-magnetic material obtained by magnetic separation is also included .

[0034] The beneficial ef fects of the present invention are as follows : di f ferent from the prior art , the present invention can remove impurities in the laterite nickel ore hydrometallurgical slag after alkali leaching and acid leaching . Furthermore , the biomass is carboni zed and activated to obtain a biomass reducing agent with enhanced reducibility . The cost of the biomass reducing agent is low and the utili zation rate of the biomass is improved . After the biomass reducing agent is further mixed with the acid leaching residue in a speci fic proportion, the reduction roasting is carried out with additives under a speci fic atmosphere , and then magnetic separation is carried out to obtain an iron concentrate with higher purity . In addition, the whole method has the advantages of short process , low cost , good recovery rate , etc . , solves the environmental problems caused by long-term storage and landfill of laterite nickel ore hydrometallurgical slag, and is conducive to large-scale promotion and invention .

[0035] Brief Description Of The Drawings

[0036] FIG . l is a flow chart of the method for recycling and utili zing laterite nickel ore metallurgical slag resources in the present invention .

[0037] Detailed Description

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention . Obviously, the described embodiments are only some of the embodiments of the present invention, not all of the embodiments . Based on the embodiments in this invention, all other embodiments obtained by those of ordinary skill in the art without creative ef forts shall fall within the scope of protection of this invention .

[0039] The experimental methods without speci fic conditions in the embodiments are usually carried out according to conventional conditions and conditions described in the manual , or according to conditions recommended by the manufacturer . The general equipment , materials , reagents , etc . used are all available from commercial channels unless otherwise speci fied .

[0040] Please refer to FIG . 1 , which is a flow chart of the method for recycling and utili zing laterite nickel ore metallurgical slag resources in the present invention . Specifically, the method includes the following steps: alkali leaching the laterite nickel ore hydrometallurgical slag to obtain alkali leaching solution and alkali leaching residue, wherein the alkali leaching solution is evaporated and crystallized to obtain a sodium sulfate product; acid leaching the alkali leaching residue to obtain acid leaching solution and acid leaching residue, wherein the acid leaching solution is evaporated and crystallized to obtain a calcium chloride product; the acid leaching residue, a biomass reducing agent and an additive are mixed and then ball milled for the first time, and the obtained product is subjected to reduction roasting treatment to obtain a roasted product; the roasted product is mixed with a dispersant and then ball milled for the second time, and the obtained product is subjected to magnetic separation to obtain an iron concentrate and a non-magnetic material, wherein the non-magnetic material is used to produce building materials or cement products.

[0041] In the present invention, the moisture content of the laterite nickel ore hydrometallurgical slag is 27-28%, Fe mainly exists in the form of Fe2Os, S and Ca mainly exist in the form of CaSCh, and Al mainly exists in the form of (H2O) Al 3 (SO4) 2 (OH) e and NaAls (SO4) 2 (OH) e; the specific components are shown in Table 1 below.

[0042] Table 1 Chemical composition of laterite nickel ore hydrometallurgical slag

[0043] Embodiment 1

[0044] In this embodiment, a biomass reducing agent is first prepared, and the specific method is as follows:

[0045] First, the coconut shell is crushed (less than 3 cm) by a crusher, and then rinsed with deionized water to remove surface impurities, dried at 100°C for 480 minutes, and then heated to 500°C at 3°C / min in a nitrogen atmosphere for 80 minutes, and naturally cooled to room temperature; the resulting product is activated by heating to 500°C at 3°C / min in a carbon dioxide atmosphere for 40 minutes, and naturally cooled to room temperature; the activated biochar is crushed and ground with an agate mortar, passed through a 150-mesh sieve, and rinsed with deionized water 4 times to remove impurities, and then dried at 110°C for 680 minutes to obtain a biomass reducing agent. Then, the laterite nickel ore metallurgical slag resources are recycled, and the specific method includes the following steps:

[0046] 51, Placing the laterite nickel ore hydrometallurgical slag in a NaOH solution with a concentration of 1.5 mol / L, and controlling the solid-liquid ratio to lg:7mL, stirring for 100 minutes at a temperature of 75°C and a rotation speed of SOOrpm to obtain an alkaline leaching solution and alkaline leaching residue; continuing to evaporate and crystallize the alkaline leaching solution at a temperature of 85°C for 180 minutes to obtain a sodium sulfate product;

[0047] 52. Place the alkaline leaching residue obtained in step SI in a 1.5 mol / L HC1 solution, and control the solid-liquid ratio to lg:7 mL . Stir for 100 min at a temperature of 75 °C and a rotation speed of 300 rpm to obtain an acid leaching solution and acid leaching residue; continue to evaporate and crystallize the acid leaching solution at a temperature of 60 °C for 180 min to obtain a calcium chloride product;

[0048] 53. Add a biomass reducing agent accounting for 2% of the mass of the acid leaching residue and Na2CO3 accounting for 4% of the mass of the acid leaching residue to the acid leaching residue obtained in step S2, mix and evenly ball mill in a ball mill for 80 min, and then ball mill the product is placed in an atmosphere furnace, argon is introduced at a flow rate of 3 mL / min, and the temperature is raised to 700°C at a rate of 5°C / min for reduction roasting for 100 minutes to obtain a roasted product;

[0049] 54, Sodium metaphosphate accounting for 3% of the mass of the roasted product is added to the roasted product obtained in step S3, and then ball milled for 30 minutes, and the amount of water added is 5 times the mass of the solid material to obtain an intermediate slurry, and then the intermediate slurry is magnetically separated under the condition of a magnetic separation intensity of 2000 Gs, and the iron concentrate product and non-magnetic material are obtained after filtering and drying. The non-magnetic material is used to produce building materials or cement products. Embodiment 2

[0050] In this embodiment, a biomass reducing agent is first prepared, and the specific method is as follows:

[0051] First, the fruit tree branches are crushed by a crusher (less than 3 cm) , then rinsed with deionized water to remove surface impurities, dried at 100°C for 480 minutes, and then heated to 500°C at 3°C / min in a nitrogen atmosphere for 100 minutes, and naturally cooled to room temperature; the resulting product is activated by heating to 500°C at 3°C / min in a carbon dioxide atmosphere for 50 minutes, and naturally cooled to room temperature ; the activated biochar is crushed and ground with an agate mortar, passed through a 150-mesh sieve, and rinsed with deionized water 4 times to remove impurities, and then dried at 115°C for 720 minutes to obtain a biomass reducing agent.

[0052] Then the laterite nickel ore metallurgical slag resources are recycled, and the specific method includes the following steps:

[0053] 51, Placing the laterite nickel ore hydrometallurgical slag in a NaOH solution with a concentration of 1.5 mol / L, and controlling the solid-liquid ratio to 1g: 7mL, stirring for lOOmin at a temperature of 75°C and a rotation speed of 300rpm to obtain an alkaline leaching solution and an alkaline leaching residue; continuing to evaporate and crystallize the alkaline leaching solution at a temperature of 85°C for 180min to obtain a sodium sulfate product;

[0054] 52, Placing the alkaline leaching residue obtained in step SI in a HC1 solution with a concentration of 1.5 mol / L, and controlling the solid-liquid ratio to 1g: 7mL, stirring for lOOmin at a temperature of 75°C and a rotation speed of 300rpm to obtain an acid leaching solution and an acid leaching residue; continuing to evaporate and crystallize the acid leaching solution at a temperature of 60°C for 180min to obtain a calcium chloride product;

[0055] 53. Add 3% of the mass of the biomass reducing agent and 4% of the mass of the Na2CO3 to the acid leaching residue obtained in step S2, mix and evenly ball mill for 80 minutes in a ball mill, then place the ball-milled product in an atmosphere furnace, and introduce argon at a flow rate of 3mL / min; and heat to 700°C at a rate of 5°C / min for reduction roasting for lOOmin to obtain a roasted product;

[0056] 54. Add 4% of the mass of the sodium metaphosphate to the roasted product obtained in step S3, mix and ball mill for 30min, then add water in an amount of 5 times the mass of the solid material to obtain an intermediate slurry, and then perform magnetic separation on the intermediate slurry under the condition of a magnetic separation intensity of 2000Gs, filter and dry to obtain iron concentrate products and non-magnetic material, and the non-magnetic material are used to produce building materials or cement products.

[0057] Embodiment 3

[0058] In this embodiment, a biomass reducing agent is first prepared, and the specific method is as follows:

[0059] First, the coconut shell is crushed (less than 3 cm) by a crusher, and then rinsed with deionized water to remove surface impurities, dried at 100°C for 480 minutes, and then heated to 500°C at 3°C / min in a nitrogen atmosphere for carbonization for 120 minutes, and naturally cooled to room temperature; the resulting product is activated by heating to 500°C at 3°C / min in a carbon dioxide atmosphere for 60 minutes, and naturally cooled to room temperature; the activated biochar is crushed and ground with an agate mortar, passed through a 150-mesh sieve, and rinsed with deionized water 4 times to remove impurities, and then dried at 117°C for 720 minutes to obtain a biomass reducing agent.

[0060] Then, the laterite nickel ore metallurgical slag resources are recycled, and the specific method includes the following steps:

[0061] 51, Placing the laterite nickel ore hydrometallurgical slag in a NaOH solution with a concentration of 2 mol / L, and controlling the solid-liquid ratio to be lg:7mL, stirring for 100 minutes at a temperature of 75°C and a rotation speed of 300rpm to obtain an alkaline leaching solution and alkaline leaching residue; continuing to evaporate and crystallize the alkaline leaching solution at a temperature of 85°C for 180 minutes to obtain a sodium sulfate product;

[0062] 52, Placing the alkaline leaching residue obtained in step SI in a 1.5 mol / L HC1 solution, controlling the solid- liquid ratio to 1g: 7mL, stirring for 100 min at a temperature of 75 °C and a rotation speed of 300 rpm to obtain an acid leaching solution and acid leaching residue; continuing to evaporate and crystallize the acid leaching solution at a temperature of 60 °C for 180 min to obtain a calcium chloride product 53. Add 4% of the mass of the biomass reducing agent and 4% of the mass of the Na2CO3 to the acid leaching residue obtained in step S2, mix and evenly ball mill for 80 minutes in a ball mill, then place the ball-milled product in an atmosphere furnace, and introduce argon at a flow rate of 3mL / min; and heat to 700°C at a rate of 5°C / min for reduction roasting for lOOmin to obtain a roasted product;

[0063] 54. Add 4% of the mass of the sodium metaphosphate to the roasted product obtained in step S3, mix and ball mill for 30min, then add water in an amount of 5 times the mass of the solid material to obtain an intermediate slurry, and then perform magnetic separation on the intermediate slurry under the condition of a magnetic separation intensity of 2000Gs, filter and dry to obtain iron ore concentrate products and non-magnetic materials, and the non-magnetic materials are used to produce building materials or cement products.

[0064] Embodiment 4

[0065] In this example, a biomass reducing agent is first prepared, and the specific method is as follows:

[0066] First, the coconut shell is crushed (less than 3 cm) by a crusher, and then rinsed with deionized water to remove surface impurities, dried at 100°C for 480 minutes, and then heated to 500°C at 3°C / min in a nitrogen atmosphere for carbonization for 160 minutes, and naturally cooled to room temperature; the resulting product is activated by heating to 500°C at 3°C / min in a carbon dioxide atmosphere for 70 minutes, and naturally cooled to room temperature; the activated biochar is crushed and ground with an agate mortar, passed through a 150-mesh sieve, and rinsed with deionized water 4 times to remove impurities, and then dried at 120°C for 800 minutes to obtain a biomass reducing agent.

[0067] Then, the laterite nickel ore metallurgical slag resources are recycled, and the specific method includes the following steps:

[0068] SI, Placing the laterite nickel ore hydrometallurgical slag in a Na2CO3 solution with a concentration of 1.5 mol / L, and controlling the solid-liquid ratio to lg:7mL, stirring for 100 minutes at a temperature of 75°C and a rotation speed of 300rpm to obtain an alkaline leaching solution and alkaline leaching residue; continuing to evaporate and crystallize the alkaline leaching solution at a temperature of 85°C for 180 minutes to obtain a sodium sulfate product; 52 , Placing the alkaline leaching residue obtained in step S I in a 1 . 5 mol / L HC1 solution, controlling the solid-liquid ratio to lg : 7 mL, stirring for 100 min at a temperature of 75 ° C and a rotation speed of 300 rpm to obtain an acid leaching solution and acid leaching residue ; continuing to evaporate and crystalli ze the acid leaching solution at a temperature of 60 ° C for 180 min to obtain a calcium chloride product ;

[0069] 53 , Adding a biomass reducing agent accounting for 5% of the mass of the acid leaching residue and Na2CO3 accounting for 6% of the mass of the acid leaching residue obtained in step S2 , and evenly ball-milling the mixture in a ball mill for 80 minutes after mixing . Then, the ball-milled product is placed in an atmosphere furnace , and argon is introduced at a flow rate of 3 mL / min; and the temperature is increased to 700 ° C at a rate of 5 ° C / min, and reduction roasted for 100 minutes to obtain a roasted product ;

[0070] 54 , Adding 5% sodium metaphosphate by weight of the calcined product to the calcined product obtained in step S3 , mix and ball-mill for 30 minutes , then add water in an amount of 5 times the weight of the solid material to obtain an intermediate slurry, and then perform magnetic separation on the intermediate slurry under the condition of a magnetic separation intensity of 2000 Gs , filter and dry to obtain an iron concentrate product and a non-magnetic material , and the non-magnetic material is used to produce building materials or cement products .

[0071] Comparative Example 1

[0072] The method for recycling and utili zing the laterite nickel ore metallurgical slag resources in this comparative example is basically the same as that in Embodiment 1 , except that in step S3 , the amount of biomass reducing agent added accounts for 0 . 5% of the mass of the acid leaching residue .

[0073] Comparative Example 2

[0074] The method for recycling and utili zing the laterite nickel ore metallurgical slag resources in this comparative example is basically the same as that in Embodiment 1 , except that the laterite nickel ore hydrometallurgical slag is not subj ected to the treatment in steps S I and S2 , but directly subj ected to the treatment in steps S3 and S4 . The yield and purity of the iron concentrate recovered in Embodiments 1-4 and Comparative Examples 1-2 were tested, and the results are shown in Table 2 .

[0075] Table 2 Iron Concentrate Yield and Purity Results

[0076] It can be seen from the data in Table 2 that the methods in this invention are used to recycle the laterite nickel ore metallurgical slag resources in Embodiments 1-4 to obtain iron concentrate products with higher purity . In Comparative Example 1 , the amount of biomass reducing agent added was reduced, and it was found that the purity of the iron concentrate product was signi ficantly reduced . The results show that by controlling the amount of biomass reducing agent added within a speci fic range , the purity of the iron concentrate product can be improved . In Comparative Example 2 , the laterite nickel ore hydrometallurgical slag was not subj ected to alkali leaching and acid leaching treatment . It was found that the purity of the iron concentrate product was signi ficantly reduced . The results show that after impurities are removed by alkali leaching and acid leaching, the purity of the iron concentrate product can be improved .

[0077] In summary, in this invention, after the laterite nickel ore hydrometallurgical slag is subj ected to alkali leaching, acid leaching, reduction roasting and magnetic separation in sequence , not only iron concentrate product can be obtained, but also by-product sodium sul fate product and calcium chloride product can be obtained, and the obtained non-magnetic material can be used to produce building materials or cement products . This method greatly improves the resource utili zation rate of laterite nickel ore metallurgical slag . It should be noted that the above embodiments all belong to the same inventive concept , and the descriptions of the embodiments have di f ferent focuses . For any details not described in individual embodiments , please refer to the descriptions in other embodiments .

[0078] The above embodiments only express the implementation methods of the present invention, and the descriptions are relatively speci fic and detailed, but they cannot be understood as limiting the scope of the invention patent . It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention . Therefore , the protection scope of the patent of this invention shall be based on the attached claims .

Claims

Claims1. A method for recycling and utilizing laterite nickel ore metallurgical slag resources, characterized in that it comprises the following steps:Subjecting alkaline leaching treatment to the laterite nickel ore hydrometallurgical slag to obtain alkaline leaching solution and alkaline leaching residue;Subjecting acid leaching treatment to the alkaline leaching residue to obtain acid leaching solution and acid leaching residue;The acid leaching residue, biomass reducing agent and additive are mixed and subjected to a ball milling treatment, and the obtained product is subjected to a reduction roasting treatment to obtain a roasting product;The roasting product is mixed with a dispersant and subjected to a secondary ball milling treatment, and the obtained product is subjected to magnetic separation to obtain an iron concentrate;Wherein, in the preparation process of the roasting product, the biomass reducing agent is obtained by carbonizing and activating the biomass .

2. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1, characterized in that, in the preparation process of the alkali leaching solution and the alkali leaching residue, the laterite nickel ore hydrometallurgical slag comprises the following components in mass percentage: 40-45% iron, 5-9% sulfur, 1.5-3% calcium and 3-6% aluminum.

3. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1, characterized in that, in the preparation process of the alkaline leaching solution and the alkaline leaching residue, the alkaline leaching treatment step specifically comprises: placing the laterite nickel ore hydrometallurgical slag in an alkaline solution, controlling the solid-liquid ratio to be 1g: (4-10)mL, and stirring for 60-140min at a temperature of 60-90°C and a rotation speed of 200-400rpm;Wherein, the concentration of the alkali solution is 1-2 mol / L, and the alkali solution includes NaOH solution and / or Na2CO3 solution.

4. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, in the process of preparing the alkaline leaching solution and the alkaline leaching residue, it also includes the step of evaporating and crystallizing the alkaline leaching solution to obtain a sodium sulfate product;Wherein, the evaporation and crystallization specifically includes: evaporation and crystallization for 160-200 minutes at a temperature of 75-95°C.

5. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, in the process of preparing the acid leaching solution and the acid leaching residue, the acid leaching treatment step specifically comprises: placing the alkali leaching residue in an acid solution, controlling the solid-liquid ratio to 1g: (4-10)mL, and stirring for 60-140min at a temperature of 60-90°C and a rotation speed of 200-400rpm;Wherein, the concentration of the acid solution is l-2mol / L, and the acid solution comprises an HC1 solution.

6. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, in the process of preparing the acid leaching solution and the acid leaching residue, it also includes the step of evaporating and crystallizing the acid leaching solution to obtain a calcium chloride product;Wherein, the evaporation and crystallization specifically includes: evaporation and crystallization for 160-200 minutes at a temperature of 30-90°C.

7. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, in the preparation process of the roasted product, the stepof carbonizing and activating the biomass specifically comprises: crushing the biomass, heating it to 350-600°C at a rate of l-5°C / min for carbonization for 80-160min under an inert atmosphere; heating the obtained product to 350-600°C at a rate of l-5°C / min for activation for 40-70min under a carbon dioxide atmosphere;Wherein, the biomass includes at least one of coconut shell, wheat straw, corn straw, bamboo, rice straw, peanut shell, and tree branch, and the inert gas includes nitrogen and / or argon.

8. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, during the preparation of the roasted product, the amount of the biomass reducing agent added accounts for 2-5% of the mass of the acid leaching residue, and the additive is Na2CO3 and / or NaOH, and the amount of the additive added accounts for 4-6% of the mass of the acid leaching residue;The first ball milling step specifically includes: ball milling in a ball mill for 30-120 minutes;The reduction roasting step specifically includes: placing the mixed material in an atmosphere furnace, while introducing an inert gas at a flow rate of l-5mL / min; and heating to 500-900°C at a rate of 3-6°C / min and roasting for 30-180min;Wherein, the inert gas includes argon.

9. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, during the preparation of the iron concentrate, the amount of the dispersant added accounts for 3-5% of the mass of the roasted product, and the dispersant includes at least one of sodium metaphosphate, sodium hexametaphosphate, water glass, caustic starch and salted water glass;The secondary ball milling treatment step specifically includes: the ball milling time is 20-40 minutes.

10. The method for recycling and utilizing laterite nickel ore metallurgical slag resources according to claim 1 is characterized in that, in the preparation process of the iron concentrate, beforethe obtained product is subj ected to magnetic separation, it also includes the step of adding water to the obtained product for slurry treatment to obtain an intermediate slurry, and subj ecting the intermediate slurry to magnetic separation;Wherein, the mass of water added is 4- 6 times the mass of the obtained product ; the magnetic separation speci f ically includes : conducting magnetic separation under the condition of a magnetic separation intensity of 1000-3000GS .

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